Abstract
In a previous paper we showed that the microsomal DPNH-diaphorase activity might be concerned with cell mitosis. The present study was undertaken to determine how microsomal DPNH-diaphorase activities differ among tissues in which cell mitosis is active or inactive. Cell fractions were prepared by the usual Strittmatter's method, and the mitochondrial contamination was calculated on the basis of succinic dehydrogenase activity. The mitochondrial DPNH-diaphorase activity was higher than the microsomal activity in liver, kidney, heart muscle and skeletal muscle. On the contrary, the microsomal DPNH-diaphorase activity was much higher than the mitochondrial activity in the intestinal mucosa in which cell mitosis is active.
